Induction coil



Nov. 24, 1936. P. PIFFATH INDUCTION COIL Filed Feb. 8, 1936 a; Z6 T Z5 Z5 Z/ 3 Z/ [Z /Z Z2 E W 5/; /J

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70 INVENTOR.

ATTORNEYS UNITED STATES PATENT OFFICE INDUCTION COIL Peter Piffath, Great Neck, N. Y.

Application February 6 Claims.

This invention relates to induction coils and has for an object to provide an easily assembled and tightly sealed induction coil casing having improved means for delivering the high voltage 5 current to an external terminal.

According to this invention, the laminated iron core is provided with a central lamination of longer length than the remaining laminations which projects beyond the end of the core. The casing 10 cover is of insulating material and has molded therein a metal post having at its inner end a slot which frictionally receives the exposed end of the central lamination. Assembly is effected merely by placing the casing cover on the 15 casing after the coil assembly has been placed in the casing and joining together the cover and casing. Leakage of moisture through the cover is effectively prevented since there is no opening therein and the post is equipped with a suitable terminal, the secondary winding of the coil being electrically connected to the iron core.

Other objects, novel features and advantages of this invention will become apparent from the following specification and accompanying draw- 25 ing, wherein:

Fig. 1 is a vertical section of an induction coil embodying the invention;

Fig. 2 is a section on the line 2--2 of Fig. 1;

Fig. 3 is an enlarged fragmentary view similar 30 to Fig. 2;

Fig. 4 is a section on the line 4-4 of Fig. 3 and Fig. 5 is an inverted plan view of the inner end of the post.

A fluted metal casing I is provided with an in- 35 sulator l I which rests on the bottom of the casing and an insulating cover l2 having an annular recess which receives the upper end of the casing. The casing I0 is attached to the cover [2 by having a rib l3 spun into a co-acting annular groove 40 provided in a flange l4 constituting a portion of the cover. The induction coil consists of a primary winding I enclosing a secondary winding [6, an insulator I! being provided between them.

Within the bore of the secondary winding I6 is arranged the usual laminated iron core l8 between which and the secondary winding is interposed an insulator IS. The core I8 is of greater length than the coil so that both ends of the core project beyond the ends of the coil. The core is elec- 50 trically connected as at 20 to one end of the secondary winding. The bottom end of the core is seated in a recess in the insulator H which acts as a support for the coil assembly.

The central lamination of the core I8 is of 55 greater length than the remaining laminations 8, 1936, Serial No. 62,878

and so projects beyond the upper end of the core. In the cover i2 is molded a metal post 21 having at its bottom end a trough-shaped recess terminating in a slot 22 of such width as to frictionally receive the exposed end of said central lamination. Also molded in the head l2 are combined posts 23 and 24, the former of which is connected to one end of the primary winding and the latter of which is connected to the remaining end of the primary winding and to the remaining end of the secondary winding. At its outer end the post 2| is provided with a socket 25 in which fits a terminal member 26.

In assembling the device above described, electrical connection is assembled between the central lamination of the core and the post 2| merely by placing the cover [2 on the casing H), the upper end of the central lamination being guided into the slot 22 by the trough-shaped groove in the bottom end of the post. The wires leading to the binding posts 23 and 24 from the primary and secondary windings are passed through the bores in the binding posts before the cover is placed on the casing, are pulled taut and are connected to the binding posts by soldering in the usual manner. The casing is attached to the cover by rolling the rib l3 into its co-operating groove in the flange I4. The coil is held firmly in the casing by engagement of the bottom and upper ends thereof with the flanges Ila and 12a respectively on the insulator I l and the cover l2.

When the device above described is connected up for operation, the terminal 23 is connected to the positive terminal of a source of direct current, the terminal 24 is connected to ground and the terminal 26 is connected to the electrical instrument to which it is desired to supply high voltage current. Leakage of moisture through the cover is efiectively prevented since the arrangement of a solid post molded in the cover avoids the requirement of an aperture for the customary wire leading to the high voltage terminal.

I claim:

1. A device of the character described comprising a casing having an insulated cover, a metal post molded in said cover and having a transverse slot in its inner end, and an induction coil within said casing and having its core composed of laminations of which one projects beyond the end of the core and extends into said slot.

2. A device of the character described according to claim 1 in which said post has a bore in its outer end and a terminal member is inserted therein.

3. A device of the character described comprising a casing having an insulated cover, an insulator in the bottom of said casing, said cover and insulator having inwardly directed flanges, an induction coil interposed between said flanges, said coil having its core composed of laminations one of which projects beyond the upper end of said core, and a metal post molded in said cover, said post having a transverse slot in its inner end into which extends the end of said projecting lamination.

4. A device of the character described according to claim 3 in which said post has a bore in its outer end and a terminal inserted therein.

5. A device of the character described comprising a metal casing having an insulated cover, an insulator in the bottom of said casing, an induction coil within said casing, said coil having its core composed of laminations of which one projects beyond the upper end of the core, said core extending beyond the ends of said coil and being seated in said insulator and cover, and a metal post molded in said cover, said post having a. transverse slot in its inner end into which extends the end of said projecting lamination.

6. A device of the character described comprising a cylindrical metal casing, an insulated cover having a circular groove receiving the edge of said casing and an annular flange engaging the inner periphery of the casing, said flange having a peripheral groove and said casing having an annular rib projecting into said groove, an induction coil contained within said casing and having a core composed of laminations, one of which projects beyond the upper end of said core, and a metal post molded in said head, said post having a transverse slot in its inner end into which extends the end of said projecting lamination.

PETER PIFFATH. 20 

